Paper machinery



April 15,- 1958 Y J. BAXTER, JR 2,830,503

PAPER MACHINERY Filed Oct. 15,1954 e Sheets-Sheet 1 INVENTdR. JOSEPHBAXTER, JR.

Q W ATTORNEYS April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 2 Filed 001;. 13, 1954 IN VEN TOR.

-w\ JOSEPH BAXTER,JR.

April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 3 Filed Oct. 13, 1954 Ma T.

mm Mm ll/ T A we aw m m/ 5 mm mm m April 15, 1958 J. BAXTER, JR

PAPER MACHINERY 6 Sheets-Sheet 4 Filed 001;. 13, 1954 mm v M N E R VX 0N T [B M H P E.,, SW mw VIM April 15, 1958 J. BAXTER, JR 2,830,503

PAPER MACHINERY Filed Oct. 13, 1954 6 Sheets-Sheet 5 Fl G 9 CLUTCH BRAKEon OFF TUBE TER 210 REJECT COUNTER IN VEN TOR.

JOSEPH BAXTER, JR.

ATTORNEYS April 15, 1958 J. BAXTER, JR 2,830,503

' PAPER MACHINERY Fil ed Oct. 15, 1954 s Sheets-Sheet e FIG-ll INVENTOR.

JOSEPH BAXTER, JR. BY

ATTOR NEYS PAPER MACHINERY Joseph Baxter, Jr., Franklin, Ohio, assignorto The Black Ciawson Company, Hamilton, Ohio, a corporation of ioApplication October 13, 1954, Serial No. 462,093

Claims. (CI. 92-66) This invention relates to the manufacture of tubesof paperboard and other web materials.

Among the primary objects of the invention is the provision of apparatusfor continuously forming a series of tubes of predetermined length bywinding a web of sheet material such as paper or plastic on successivemandrels which are indexed in caged position at a forming station,rotated to wind the web thereon until a tube of the desired thicknesshas been built up thereon, and then released and replaced by a newmandrel on which the next tube is formed.

A particular object of the invention is to provide such apparatuswherein the operation may be essentially automatic, with the apparatusperforming according to a definite cycle which is automatically startedby completion of the winding of a tube to the desired thickness andwhich includes automatic removal of each finished tube followed bydelivery and indexing of each successive new mandrel to the formingstation for winding of the next tube thereon.

An additional object of the invention is to provide such automatic tubeforming apparatus which also includes selective controls for manualoperation thereof and especially for selective interruption of theregular cycle of the apparatus in the event of improper formation of agiven tube. I

Another object of the invention is to provide apparatus as outlinedabove for forming tubes of paperboard which includes a paperboardmachine continuously forming and delivering a wet paper web to theforming station for the tubes, and particularly to provide suchapparatus wherein the same belt which receives the paper web from thepaper machine also delivers the paper web to the tube forming stationand aids in the operation of windingthe paper web on successive mandrelsat the forming station.

It is also an object of the invention to provide tube forming apparatusas outlined above which is quickly and easily adjusted as desired tovary the thickness of the tubes formed thereby without otherwiseaffecting the operation of the apparatus as a whole.

Many other objects and advantages of the invention will be apparent fromthe following description, the accompanying drawings and the appendedclaims.

In the drawings- Fig. 1' is a somewhat diagrammatic view in the natureof a sectional perspective illustrating tube forming apparatusconstructed in accordance with the invention;

Fig. 2 is a somewhat diagrammatic elevational view of a portion of theapparatus of Fig. 1 and looking in the opposite direction from Fig. 1;

Fig. 3 is an enlarged view of a fragment of one of the conveyors whichcarries the mandrels on which the tubes are formed; v

Fig. 4 is an enlarged fragmentary view showing certain of the limitswitches which control operation of the apparatus;

Fig. 5 is an elevational view of the press section of United StatesPatent the apparatus of Figs. 1 and 2 which defines the formin stationfor the tubes;

Fig. 6 is a plan view of the press section of Fig. 5;

Fig. 7 is a section on the line 7--7 of Fig. 5;

Fig. 8 is a fragmentary view looking in the direction indicated by theline 88 of Fig. 6;

Fig. 9 is a wiring diagram; and

Figs. 10-14 are fragmentary diagrammatic views illustrating successivesteps in the tube forming operation of the apparatus of Figs. 1-9.

Referring to the drawings, which illustrate a preferred embodiment ofthe invention, Fig. 1 illustrates in diagrammatic fashion the generalarrangement and mode of operation of the apparatus, and Fig. 2illustrates in more detail the tube forming portions of the apparatus.The successive mandrels it on which the tubes 11 are formed are carriedduring operation of the apparatus by a pair of continuous sprocket chainconveyors 13 carried by sprockets 1 on a plurality of shafts 15 mountedon a framework identified generally as 16. An adjustable take-up unit 17provides for maintaining proper tension of the chain conveyors 13. Eachconveyor also has pivoted thereon a plurality of successive blocks 20each having a slot 21 therein for receiving one end of a mandrel, andguiding angles 22 hold the mandrels in place in those portions of thetravel of the conveyors wherein the slots 21 open downwardly.

The operation of this apparatus i such that the mandrels 10 are carriedsuccessively through a forming station which is defined by two pairs ofpress rolls 3033 mounted in pairs as parts of two presssectionsindicated generally at 34 and 35. These press sections are mounted forrelative transverse movement between retracted positions opening theforming station and advanced positions in which the press rolls cage onemandrel in the forming station to wind a wet paper web thereon. In theretracted positions of the press sections, the conveyors 13 remove thewound tube from the forming station and deliver a new mandrel intoposition for the next cycle of the apparatus, the conveyors beingsupported by guide plates or brackets 36 mounted on the main frameworkat either side of the machine, having slots 37 therein receiving andproviding for the reciprocating movements of the journals of the pressrolls 32 and 33. The successive mandrels having the wound tubes thereonare removed at the right hand end of the machine as viewed in Fig. l fordrying and such other subsequent treatment as may be desired.

The press rolls 3i) and 31 cooperate with a continu ous felt web 40which is threaded around a plurality tional construction, detailed"description thereof is be lieved unnecessary, and in operation theysupply a continuous wet paper web 45' to the felt 40 for delivery to theforming station, the felt 40 being continuously driven in the directionof the arrows in Fig. l by the usual drive for the couch rolls and alsothe drive for the press rolis 3% and 31 as described hereinafter. Thepaper machines 44 are indicated as provided with stock inlets 46 of theconstruction disclosed in Staege Patent No. 2,347,717, issued May 2,1944, to the assignee of this application.

'Means are provided for continuously tensioning and conditioning thefelt 40 as well as for controlling the moisture content of the paper web45. Thus the guide roll 41' is provided with a manually adjustablestretcher mechanism 50, and the guide roll 41" is automatically ad- Acontin particles of fibers which may adhere to the felt as the latterleaves the forming station, and a suction box 53 dries the felt beforeit reaches the first couch roll 42. Moisture in the paper web isregulated by a suction box 55 over which the felt 40 travels just beforereaching the forming station, and a shower pipe 56 provides forintermittently re-wetting the web to facilitate transfer from acompleted tube to a new mandrel as described hereinafter, this showerpipe having a control valve 57 (Fig. 9) of the poweropening,spring-return type and a mounting bracket 58.

The press rolls 32 and 33 in the press section 35 cooperate with asimilar felt 60 which is arranged on guide rolls 61 within thecontinuous web formed by the mandrels and conveyors 13, and it iscontinuously driven by the driving action of the press rolls 32-33. Allof these press rolls are driven in the same angular direction so thatthe felt 60 travels through the forming station in the oppositedirection from the felt 40, namely in clockwise direction as viewed inFig. l, and it is continuously conditioned by a whipper assembly 62 andsuction box 65. Manual adjustment of the tension of felt 60 is effectedby a stretcher assembly 66 for the guide roll 61, and the guide roll 61"is automatically adjustable to maintain tension in the felt 60 duringmovement of the press section 35.

The detailed construction and operation of the two press sections willbe apparent from Figs. 6-8. At the wet end of the apparatus, the presssection 34 is formed by front and rear slides 80 and 81 connected byupper and lower tie beams 82 and 83. Each of the slides 80 and 81 issupported for movement lengthwise of the apparatus by rollers 84 onrails 85, and the slides are guided at the top by guides 86 suspended bybrackets 87 from the main framework 88 of the apparatus. The press rolls30 and 31 are journaled in vertical alignment in the slides 80 and 81,and they are provided with three backing rolls 90 carried by side frames91 connected by a tie frame 92 and mounted for sliding movement withrespect to the press rolls by means of side plates 93 slidable onbrackets 94 secured to the tie beam 83. A pair of air cylinders 95 aremounted on an I-beam 96 and are connected at 97 with the backing rollframe parts 91-92 to vary the supporting pressure of the backing rollsagainst the press rolls as desired. The main base for this part of theapparatus is identified generally as 99.

The press section 35 at the right hand or tube end of the apparatus isof essentially the same construction, and it includes slides 100 and 101connected by tie beams 102 and 103 and provided with similar rollers 104running on the rails 85, with the upper ends of these slides beingguided similarly to the slides 80-81 by guides 86. The press section 35also includes backing rolls 105 mounted similarly to the backing rolls90 as indicated by similarly identified parts provided with aircylinders 106 corresponding to the cylinders 95 and similarly mounted tosupply controlled backing pressure through the rolls 105 to the pressrolls 32 and 33.

As stated, the two press sections are movable with respect to eachother, and means are provided for effecting and controlling thismovement and also for maintaining both sections in proper parallelalignment at all times. Each of the slides 80-81 and 100-101 isaccordingly provided with a fluid pressure cylinder 110, 111 mounted onthe framework 88 and having its piston rod 112 connected to theassociated slide. The cylinders 110 and 111 are. double-acting to causealternative power advance and retraction of the press sections and tomaintain pressure thereon during formation of the tubes, and eachcylinder is.provided witha double-acting solenoid valve 115.

Relative alignment of the press sections is maintained by sprocketvchain connections between opposed slides in cooperation with torqueshafts 120 and 121 which extend between the rearward ends. of the slides80-91 and 100-101. respectively. Referringflto. Fig. 5, a chain. 123runs around. a sprocket: 125 at thefrontend ofthetorque shaft 120, andthe ends of this chain are connected by rods 126 and 127 to the frontslides and respectively. A similar chain 130 runs around a sprocket 131on the forward end of the torque shaft 121, and its ends are similarlyconnected by rods 132 and 133 to slides 80 and 100. These chainarrangements are duplicated at the back side of the apparatus so thatwhenever one slide either advances or retracts, it will not only causesimilar movement of its opposed slide, but these movements will betransmitted to the other side of the apparatus by the torque shafts tomaintain both pairs of slides in proper relation at all times andthereby to maintain the several press rolls in effectively constantparallel relation.

All of the press rolls 30-33 are continuously driven in the same angulardirection by the main drive motor through a gear transmission 151 fromwhich a separate flexible coupling 152 connects with each press roll inorder to maintain the drive throughout the operating movements of thepress sections. Provision is also made for driving one felt guide roll41a from the press roll 30. A sprocket chain 155 connects a sprocket onthe shaft of press roll 30 with an idler sprocket 156 on the basestructure 99, and a second sprocket chain 157 connects the idlersprocket 156 with a sprocket on the shaft of the felt guide roll 41a.

The tube conveyors 13 are provided with an adjustable intermittent drivewhich indexes successive mandrels 10 in the forming station. As showndiagrammatically in Fig. 1, a motor 160 is adapted to run continuouslyduring operation. of the apparatus and to drive one sprocket shaft 15through an air clutch 161, and the shaft 15' is also provided with anair brake 162. The arrangement is such that when clutch 161 is engaged,the shaft 15' is driven to advance the conveyors 13, and the brake 162is engaged to stop the shaft 15 when clutch 161 is released. Thebrake,however, is of a type requiring power to operate it in eitherdirection, and it is not coupled to the clutch. and can be releasedwithout reengagement of the clutch.

These operations of the clutch 161 and brake 162 are controlled. duringoperation of the apparatus through electrical circuits which include alimit switch 165 mounted on the framework 16 and operated by a cam 166on a sprocket shaft 15". The switch 165 is shown as normally open, andsince a relatively small amount of rotation of the shafts 15v isrequired to advance each successive mandrel into indexed position, thecam 166 is shown as having three high-points 167 for closing switch 165.The camv 166 is preferably mounted for angular adjustment on shaft 15"to assure proper indexing operation.

Three additional limit switches are operated by the press sections 34and 35 in the manner indicated in Fig. 3. The limit switch 170, which ismounted on the fixed base 99, controls the thickness of the tubes and isoperated in response to movement of the press sections away from eachother as the result of increasing thickness of the tube' being built upon the mandrel 10 caged in the forming station. The switch 170 is shownas normally closed, but it is held open in the closed position of thepress sections by depression of its operating plunger 171 by a bracket172 mounted on one of the press section slides, shown as the slide 100.The mounting of the bracket 172isadjustable as indicated at 173 toprovide for the variation of the desired thickness of the tubes to beformed.

The other two limit switches and 181 are also mounted on the fixed base99 and are operated in response to complete retractive movement of thepress sections. The switch 180 is shown as associated with the wet endpress section 34, and it is operated by an adjustable bracket 182 on theslide 80 in the fully retracted position of press section 34. The limitswitch 181 is similarly operated. by an adjustable bracket 183 on theslide 100 in the fully retracted position of press section 35.

The sequential operationof the. apparatus is illustrated by the wiringdiagram in Fig. 9, in which for the sake of simplicity, the two sides ofthe power circuit have been indicated by plus and minus signs. Operationof the apparatus is preferably automatic as pointed out, but provisionis also made for manual control, by means of a selector switch 200 whicheffects alternative actuation of the relays RA and RM. Fig. 9 shows thecontrol circuits as set for automatic operation and with all the partsin the positions which they occupy while a tubeis being formed in theforming station. Thus all of the limit switches 165, 170, 130 and 181are open, the clutch 161 and brake 162 are both released, relay RA isenergized, but all of the other relays are open, and the solenoid valves115 are set to supply pressure to the outer ends of cylinders 110 and111 to urge the press sections together.

This stage of the operation of the apparatus is also illustrated in Fig.10, in which the partially wound tube 11b is shown on the mandrel 10b,and the last finished tube 11a is indicated as on the mandrel 10a. Thenext mandrel to be used is identified as 10c, and it is preferablyarranged as shown for engagement with the felt 60 both to bring it up tothe speed of the felt and especially to wet its surface by the moisturein the felt in order to promote a smooth start of the winding operationthereon by even addition of the wet web to the wetted mandrel. Themandrel 10b is continuously rotated by the felts 4t) and 60 as indicatedby the arrow, and it will also be apparent that while the press rolls3033 are each in pressure engagement with the tube 111; through theirassociated felts, they are out of engagement-with each other as requiredby their common angular direction of rotation.

As the thickness of the tube being wound on the caged mandrel 10bincreases, the press sections 34 and 35 are moved apart against theyielding pressure of cylinders 110 and 111 until the bracket 172releases the switch operating plunger 171, thus causing switch 170 toclose. This immediately completes the energizing circuit for relay R1.Closing of relay R1 in turn completes the proper circuit to the solenoidvalves 115 to cause the cylinders 110 and 111 to retract the presssections, this circuit running through the line 202, the uppermost pairof contacts of relay R1, line 203, the back contacts of relay R6, andlines 204 and 205, and this relative position is illustrated in Fig. 11.As the press sections reach their fully retracted positions, they actrespectively to close the limit switches 180 and 181, thus completingthe respective energizing circuits for. the relays R2 and R3. It willalso be noted that closing of relay R1 completed parallel circuitsthrough the back contacts of relays R2 and R3 for releasing brake 162.

Closing of relays R2 and R3 opens the brake-releasing circuit justdescribed leaving the brake released, and closes a circuit through theupper contacts of both of relays R2 and R3 and a line 206 to a tubecounter 210 for counting the completed tubes. In addition, closing ofrelays R2 and R3 completes an energizing circuit for the relay R4, thiscircuit running through a line 211, the lowermost contacts of relay RA,line 212, the back contacts of relay R5, and line 213.

Closing of relay R4 completes the circuit for engaging clutch 161, thiscircuit including lines 214 and 215, thereby causing the conveyor shaftto be driven for advancing the conveyors 13 and thus removing thecompleted tube on mandrel 10b from the forming station and advancing thenext mandrel 10c and 141d toward the forming station. At the same time,shaft 15" will be rotated to drive the cam 166. In addition, closing ofrelay R4 completes the circuit turning on the shower 56 to causemomentary wetting of the paper web as it approaches the forming stationand thus to facilitate pressure rupture of the web from the finishedtube and starting of the web on the new mandrel.

This stage of the operation of the apparatus is, illustrated in Fig. 12,and it continues only for the partial revolution of cam 166 required tobring the next high point 167 into closing relation with the switch 165.When this occurs, both of relays R5 and R6 will be energized by circuitsrunning through the middle contacts of both of relays RA and R1, line216, switch 165, and lines 217 and 218. Closing of relay R5 deenergizesrelay R4 and thus shuts off the shower 56. In addition, closing of relayR5 breaks the engaging circuit for clutch 161 and completes a releasingcircuit for the clutch through the line 212, the upper contacts of relayR5, and line 219.

Closing of relay R6 in efiiect reverses the pressure supply to the presssection cylinders 10-111, by opening the circuit through line 204 to thesolenoid valves and completing a new circuit to these valves throughlines 216 and 220, thus causing the press sections to start advancing toclose the forming station. Closing of relay R6 also closes a circuitcausing engagement of brake 162, this circuit running through the line212 and the lines 221, and finally relay R6 completes a hold-in circuitfor itself in parallel with switch 165.

As soon as the press sections start to close, the limit switches 180 and181 again open, thus deenergizing relays R2' and R3. This in turn opensthe brake-engaging circuit through the upper contacts of R2 and R3 andre-closes the parallel circuits through the back contacts of theserelays for releasing brake 162, so that while the tube conveyors 13 havebeen stopped, they are free to move to the extent required for centeringof the new mandrel 14 between the four press rolls in the formingstation. In addition, the adjustment of the cam 166 should be such thatthe switch will be closed to cause engagement of brake 162 just inadvance of complete movement of the mandrel 1190 into the formingstation, and this stage of the operation is illustrated in Fig. 13.

With the new mandrel 10c stopped in the position shown in Fig. 13, theclosing press rolls 30 and 31 and the felt 40 will press the wettedportion of the paper web against mandrel 100 with sufiicient pressure tocause the web to adhere thereto and to start winding thereon, therebybreaking the web from the finished tube 11b, as indicated by the tail 45in Fig. 14. In addition, as the press sections complete their closingand centering action on the new mandrel, they will in effect pull theconveyors forward the necessary small distance to rotate the camsufficiently to re-open the switch 165. As soon as this occurs, therelays R5 and R6 will be opened to re-close the back contacts of relayR6 in preparation for the next cycle. These conditions will continueonly for the interval required for complete closing of the presssections and re-opening of the limit switch 176', which will in turnopenrelay R1 to reestablish the conditions shown in Fig. 9.

Fig. 9 also illustrates provisions for partially or manual operation ofthe apparatus. For example, in place of the thickness limit switch 170,the push button switch 225 may be used to initiate the indexing cycle ofthe apparatus. The switch 225 is also useful in the event of a possiblyfaulty start of a new tube or if for any other reason the operatorwishes to reject a tube and index the machine without waiting foroperation of switch 1'79. In addition, Fig. 9 shows a reject counter 226provided with a push button switch 227 for manual operation when adefective tube is rejected.

Completely manual operation of the apparatus is provided by shifting themain switch 20% from the energizing circuit for relay RA to theenergizing circuit for relay RM. This supplies current to threeadditional manuallyoperated switches 231 231 and 232 for controllingrespectively the solenoid valves 115, the clutch 161 and the brake 162.Opening and closing of the press sections to the extent required toactuate the tube counter 210 each time the indexing cycle is repeated.In addition, a switch 235 may be provided as shown for manuallycontrolling the shower 56, this switch having On and Off manualpositions in addition to an automatic position in -which its lowercontacts are closed in series with the lower contacts of relay R4.

The invention accordingly provides reliable and efficient apparatus forthe continuous high speed formation of tubes of paper board, and theinvention also provides for accurately controlled variation of thethickness of the tubes produced by this apparatus. More specifically,the apparatus of the invention operates continuously to form a wet paperweb from paper making stock and to wind this wet web directly into thedesired tubes, which require only final drying and whatever finishingoperations may be desired, such for example as impregnation with asphaltif the tubes are to be used as conduits for electric cable, sewer orsoil pipe, and like purposes. In particular, the invention provides foraccurate automatic control of the apparatus, including control of themoisture content of the paper web as well as of the dimensions of thefully wound tube, and all conditions affecting operation of theapparatus are also readily adjusted as desired to establish the finalcharacteristics of the finished tubes.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparaus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. Apparatus for continuously forming tubes of porous fibrous webmaterial on mandrels, comprising a pair of press sections each includinga pair of press rolls in substantially vertical alignment, meansmounting said press sections for relative movement in a substantiallyhorizontal plane with said pairs of rolls in opposed relation defining aforming station for receiving and caging a single said mandrel insubstantially centered relation with all four of said press rolls, firstand second endless felt webs associated with said press sectionsrespectively and threaded between said pairs of rolls in engagement withthe associated said pair of rolls, means for continuously rotating allof said rolls in the same direction to cause said felt webs to travelthrough said forming station in opposite directions, means forcontinuously supplying a wet fibrous web to said first felt forcontinuous delivery thereby to said forming station, means connectedwith said press sections for maintaining pressure engagement of saidrolls with said caged mandrel causing said felt webs to wrap substantialportions of the periphery of said caged mandrel and thereby to rotatesaid caged mandrel with resulting winding thereon of said fibrous webinto a tube, said pressure maintaining means including yieldablepressure applying means providing for continuous retraction of saidpress sections as the thickness of said tube increases, means responsiveto increase of said tube to a predetermined total thickness foreffecting relative retraction of said press sections to open saidforming station for removal of said mandrel and said tube thereon andfor insertion of a new mandrel, and means for advancing said presssections to close said forming station and to start said fibrous webwinding on said new mandrel.

2. Apparatus for continuously forming tubes of porous fibrous webmaterial on mandrels, comprising a pair of press sections each includinga pair of press rolls in substantially vertical alignment, meansmounting said press sections for relative movement in a substantiallyhorizontal plane with said pairs of rolls in opposed relation defining aforming station for receiving and caging a single said mandrel insubstantially centered relation with all four of said press rolls, afirst and second endless felt webs associated with said press sectionsrespectively and threaded between said pairs of rolls in engagement withthe associated said pair of rolls, conveyor means for indexingsuccessive said mandrels in said forming station, means for continuouslyrotating all of said' rolls in the same direction to cause said feltwebs to travel through said forming station in opposite directions,means for continuously supplying a wet fibrous Web to said first feltfor continuous delivery thereby to said forming station, reversiblefluid pressure means for maintaining yieldable pressure engagement ofsaid rolls with each successive said caged mandrel and causing said feltwebs to wrap substantial portions of the periphery of said caged mandreland thereby to rotate said caged mandrel with resulting winding thereonof said fibrous web into a tube, means responsive to increase of saidtube to a predetermined total thickness for reversing the pressuresupply to said fiuid pressure means to effect relative retraction ofsaid press sections and opening of said forming station, means operableupon retraction of said press sections to cause said conveyor to removesaid mandrel and said tube thereon from said forming station and toindex a new mandrel in said forming station, and means for effectingadvance of said press sections to close said forming station on saidindexed mandrel and to start said fibrous web winding thereon.

3. Apparatus for continuously forming tubes of porous fibrous webmaterial on mandrels, comprising a pair of press sections each includinga pair of press rolls in substantially vertical alignment, meansmounting said press sections for relative movement in a substantiallyhorizontal plane with said pairs of rolls in opposed relation defining aforming station for receiving and caging a single said mandrel, firstand second endless felt webs associated with said press sectionsrespectively and threaded between said pairs of rolls in engagement withthe associated said pair of rolls, means for conveying a plurality ofsaid mandrels successively through said forming station, means forcontinuously rotating all of said rolls in the same direction to causesaid felt webs to travel through said forming station in oppositedirections, means for continuously supplying a wet fibrous web to saidfirst felt web for continuous delivery thereto to said forming station,yieldable means for maintaining pressure engagement of said rolls witheach successive said caged mandrel and causing said felt webs to rotatesaid caged mandrel with resulting winding thereon of said fibrous webinto a tube, means responsive to increase of said tube to apredetermined thickness for effecting relative retraction of said presssections to open said forming station for removal of said mandrel andsaid tube thereon and indexing of a new mandrel by said conveying means,means for effecting advance of said press sections to close said formingstation on said new mandrel and to start said fibrous web windingthereon, and means for causing said new mandrel to engage said secondfelt web in advance of indexing thereof in said forming station toinitiate rotation of said new mandrel and to moisten the surface thereoffor promoting a smooth start of the winding of said fibrous web thereon.

4. Apparatus for continuously forming tubes of porous fibrous webmaterial on mandrels, comprising a pair of press sections each includinga pair of press rolls in substantially vertical alignment, meansmounting said press sections for relative movement in a substantiallyhorizontal plane with said pairs of rolls in opposed relation defining aforming station for receiving and caging a single said mandrel insubstantially centered relation with all four of said press rolls, firstand second endless felt webs associated with said press sectionsrespectively and threaded between said pairs of rolls in engagement withthe associated said pair of rolls, means including an indexing conveyorarranged to carry a plurality of successive mandrels downwardly throughsaid forming station, means for continuously rotating all of said rollsin the same direction to cause said felt Webs to travel through saidformingstation in opposite directions, means for continuously supplyinga wet fibrous web to said first felt for continuous delivery thereby tosaid forming station, yieldable means for maintaning pressure engagementof said rolls with each said caged mandrel and causing said felt webs towrap substantial portions of the periphery of said caged mandrel andthereby to rotate said caged mandrel with resulting winding thereon ofsaid fibrous web into a tube, sensing means responsive to increase ofsaid tube to a predetermined total thickness for effecting relativeretraction of said press sections to open said formin station, meansresponsive to retraction of said press sections for causing saidconveyor to remove said mandrel and said tube thereon from said formingstation and to index a new mandrel in said forming station, means foreffecting advance of said press sections to close said forming stationon said indexed mandrel and to start said fibrous web winding thereon,means for effecting continuous cleaning of said felt Webs at locationsspaced from said forming station, and selectively operable means foreffecting retraction of said press sections and the removal andreplacement of said caged mandrel independently of said sensing means.

5. Apparatus for continuously forming tubes of porous fibrous Webmaterial on mandrels, comprising a pair of press sections each includinga pair of press rolls in substantially vertical alignment, meansmounting said press sections for relative movement in a substantiallyhorizontal plane with said pairs of rolls in opposed relation defining aforming station for receiving and caging a single said mandrel, firstand second endless felt webs associated with said press sectionsrespectively and threaded between said pairs of rolls in engagement withthe associated said pair of rolls, means including a continuous conveyorfor carrying a plurality of successive said mandrels downwardly throughsaid forming station, means for continuously rotating all of said rollsin the same direction to cause said first and second felt webs to travelrespectively downwardly and upwardly through said forming station, meansfor continuously supplying a Wet fiborus web to said first felt forcontinuous delivery thereto to said forming station, yieldable means formaintaining pressure engagement of said rolls with each successive saidcaged mandrel and causing said felt webs to rotate said caged mandrelwith resulting winding thereon of said fibrous web into a tube, meansresponsive to increase of said tube to a predetermined thickness foreffecting relative retraction of said press sections to open saidforming station, means responsive to opening of said forming station forcausing said conveyor to remove said caged mandrel and said tube thereonand to index the next said mandrel in said forming station, means foreffecting advance of said press sections to close said formstation onsaid next mandrel and to start said fibrous web winding thereon, andmeans cooperating with said conveyor to cause said next mandrel toengage the surface of said second felt web moving upwardly from saidcaged mandrel in advance of indexing thereof in said forming station toinitiate rotation of said next mandrel and to moisten the surfacethereof for promoting a smooth start of the winding of said fibrous webthereon.

References Cited in the file of this patent UNITED STATES PATENTS Re.17,335 Mattei et al June 25, 1929 1,147,262 Parker July 20, 19151,497,344 Parker June 10, 1924 1,786,215 Mazza Dec. 23, 1930 1,984,073Mazza Dec. 11, 1934 2,366,999 Campbell Jan. 9, 1945 FOREIGN PATENTS605,793 Germany Nov. 17, 1934

